Power series in quantum mechanics

In summary, the conversation discusses the use of the power series method to solve ODEs and how it relates to quantized energies in an infinite square well. The speaker shares their solution, which involves a power series with a variable k, and expresses concern about the lack of boundary conditions in this solution. They question the validity of their approach and ask about the location of the edges of the infinite well.
  • #1
gremory
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TL;DR Summary
Power series to solving the infinite square well
Just earlier today i was practicing solving some ODEs with the power series method and when i did it to the infinite square well i noticed that my final answer for ##\psi(x)## wouldn't give me the quantised energies. My solution was
$$\psi(x) = \sum^{\infty}_{n=0} k^{2n}(\cos(x) + \sin(x))$$, with ##k = \frac{\sqrt{2mE}}{\hbar}##. I want to know what's the catch when doing this because we need the boundary conditions to quantize the energies and with this solution i don't see how i would get that.
 
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  • #2
[tex]\psi(x) = \sum^{\infty}_{n=0} k^{2n}(\cos(x) + \sin(x))=(\cos(x) + \sin(x)) \sum^{\infty}_{n=0} k^{2n}=\psi(x,k) [/tex]

so something seems wrong. Where are the edges of infinite well ?
 
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1. What is a power series in quantum mechanics?

A power series in quantum mechanics is a mathematical representation of a quantum system that involves an infinite sum of terms. Each term in the series contains a coefficient and a variable raised to a different power. These series are used to describe the behavior of particles and their interactions in quantum mechanics.

2. How are power series used in quantum mechanics?

Power series are used in quantum mechanics to calculate the wave function of a particle, which describes the probability of finding the particle at a certain position. They are also used to calculate the energy levels of a quantum system and to determine the dynamics of a system over time.

3. What is the importance of power series in quantum mechanics?

Power series are important in quantum mechanics because they provide a way to mathematically describe the behavior of particles and their interactions at a quantum level. They allow us to make predictions and calculations about the behavior of quantum systems, which is essential in understanding the fundamental principles of the universe.

4. What are some common examples of power series in quantum mechanics?

One common example of a power series in quantum mechanics is the Taylor series, which is used to approximate the wave function of a particle. Another example is the perturbation series, which is used to calculate the energy levels of a system when a small perturbation is applied.

5. Are there any limitations to using power series in quantum mechanics?

While power series are a useful tool in quantum mechanics, they do have some limitations. For example, they may not accurately describe the behavior of particles in certain extreme conditions, such as near black holes or at very high energies. Additionally, the infinite nature of power series can make calculations and predictions difficult and time-consuming.

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